Release ska3-flight 2023.9

[javierggt]

Packages to include

Package and Test

• Create branch named 2023.9-branch
• Create PR titled 2023.9 from 2023.9-branch into master
• Create a pre-release 2023.9rc{N} at the latest commit in the branch
• Check packages are built and automated tests pass.
• Promote packages from masters to test conda channel (skare3-promote --to test ...).
• List in PR any data products that need to be promoted to $SKA/data (check PR's interface impacts).
• Install on HEAD and GRETA Linux test environments (ska3/test).
• Confirm that test data (SKA/data) is appropriate for release testing (any custom test data is set or previous test data cleaned out)
• Run testr on HEAD and GRETA
• Add related issues to PR (skare3-milestone-issues ...).
• Document all changes (skare3-changes-summary ...).
• Write summary + highlight relevant changes.
• Document test results (skare3-test-dashboard ...).
• Create FSDS Jira ticket and wait for approval.

Promote:

• Promote packages to flight conda channel (skare3-promote ...).
• Announce to aca@cfa/slack.
• Update ska3/flight on HEAD as aca user.
• Update ska3/flight on GRETA as SOT user.
• Promote any data products listed in PR to be promoted.
• Run ska_testr on HEAD and GRETA.
• Document test results (skare3-test-dashboard ...).
• Announce to aca@cfa/slack.
• Announce to sot@cfa and fot@ipa.
• Merge PR.